Fluorosurfactants are known and described generally in “Fluorinated Surfactants” by E. Kissa, Surfactants Science Series, Vol. 50 (Marcel Dekker, New York 1994). Fluorosurfactants including those derived from C4 perfluoroalkyl groups are also described in U.S. Pat. Nos. 4,167,639, 3,906,027, 5,342,986 and 5,502,251. In particular, fluorochemical surfactants derived from nonafluorobutanesulfonyl fluoride (PBSF) have been described more recently in WO 01/30873 stating that the PBSF derived surfactants are almost as effective as the known premier surfactants derived from perfluorooctanesulfonyl fluoride (POSF). Furthermore, such surfactants have been described as more environmentally friendly. There remains a need to improve on the effectiveness and efficiency of such PBSF-derived fluorosurfactants.